1. Field of the Invention
The invention concerns a connector for a hose or a rigid pipe, in particular, for use in a high pressure hydraulic circuit, comprising, on the one hand, a female part in which the free end of a pipe to be connected is inserted, a female part being formed by a body which includes, from the base, a cylindrical bore with a diameter at least equal to the external diameter of the pipe to be connected, a housing and a restriction defining, together with the latter, a shoulder and, on the other hand, clip-in-type locking devices comprising retractable stops positioned between the shoulder formed in the body and, on the rear face, a peripheral flange or rim formed on the pipe to be connected, this preventing its release from the female part.
This invention is applicable to any installation through which a fluid is conveyed and which may or may not be subject to high pressures and, more particularly, in those industries specializing in the application of hydraulics.
2. Description of Background and Relevant Information
Those types of connectors most frequently used provide a connection between pipes through which a fluid is conveyed, in particular, under high pressure, comprising, on the one hand, a female part which includes a threaded bore into which the free end of the pipe to be connected is inserted. On the other hand, the connector comprises a male part which is in the form of a sleeve or bush fixed over the pipe and including, over its external circumference, a threaded section which is designed to co-operate with the thread provided in the bore of the female part.
More precisely, this male part engages the pipe at the rear of a peripheral rim or flange so that, after being screwed in and tightened into the female part, the pipe is immobilize in this latter part by the resulting action on the rear face of the said peripheral rim or flange.
The design of these connecters for pipes subject to high pressures is in no way suitable for existing assembly methods. In large scale manufacturing, such as, the automobile industry, use is being increasingly made of robots in order to assemble the various parts comprising these components.
This is particularly so in the case of fitting and assembling sheet metal parts, the engine, the instrument panel and certain electrical wiring installations with their connection to the various different control units or other items.
However, this method of assembly using robots requires compliance with certain conditions. In particular, the connection of parts to be assembled must be easily carried out without the need for any specific dexterity. Also, it is necessary to take into consideration that the gripping devices fitted to automatic machines, that is, robots, are only suitable for carrying out very simple movements of limited scope.
Also, if these gripping devices are capable of displacement, without too much difficulty, by translation, in order to move from one point to another, the amount of angular displacement which it is possible to impart is still, however, limited. Therefore, use is very frequently made of pneumatic methods to provide a constant rotational movement, this corresponding, for example, to a screwing down action.
Another point which should be taken into consideration is that the various different parts are generally held by a simple tightening action provided by suitably shaped clamping or gripping devices.
Also, the part to be assembled must be easily accessible because of the overall dimensions generally possessed by these gripping devices fitted to robots.
Further to the above explanation, it will be easily understood that those connectors where the male part is introduced into the female part by means of a screw down action are, at present, assembled manually as no suitable automatic technique has been determined.
Another disadvantage concerning a screw type assembly is due to the amount of tightening required for the male part in the female part. The level or amount of thightening action effected is random in nature as it is difficult to reproduce. However, the performance of a connector, regarding time and the pressure involved, will depend on this tightening torque applied to the male part.
Also, other types of connections are available, these being known as rapid action types, the basic characteristic consisting in that the male part assembled onto the pipe to be connected is rendered integral with the female part following a simple axial pressure.
More precisely, the male part is in the form of a tubular end piece which includes, on its external circumference, a groove into which a number of balls are introduced, after engaging the female part, these balls being positioned in a slot provided in the bore of the latter part. These balls are then immobilized radially by means of a sleeve which moves axially over the female part.
More precisely, these connectors constitute components forming a connection between two pipes originating from separate items of equipment. Therefore, it is necessary to use connectors such as those described above in order to provide a connection between these pipes and the said items of equipment. Also, these connectors are particularly expensive because of their difficult and complex design.
In accordance with document U.S. Pat. No. 3,826,523 another type of rapid action connector is known, this being used for a hydraulic circuit conveying a fluid under pressure. More precisely, this connector comprises a female part in the form of a body into which the free end of the pipe to be connected is inserted.
This includes, at this free end, a peripheral rim or flange which enables it to be immobilized in the female part by means of the male component. This latter is, more particularly, in the form of a clip-in ring threaded over the pipe to be connected, at the rear of the peripheral rim or flange.
This clip-in ring co-operates with the rear face of this latter part and, simultaneously, with a shoulder provided in the housing or location formed by the body, this constituting the female part, in order to prevent any movement by translation of the said pipe being connected in this latter part.
Also, in accordance with the method of construction described in this prior document, this female part or the body, when considered from the base of this latter part, comprises a bore with a diameter suitable for the pipe being connected, this bore emerging in a first shoulder recess in which the seal is located. This co-operates with the front face of the peripheral rim or flange corresponding to the pipe to be connected. This peripheral rim or flange is located in a housing with a slightly increased diameter in order that the part may be engaged and removed. It should be noted that this housing and, in particular, the rear face of the said peripheral rim or flange, includes a machined slot which defines the shoulder against which the locking devices for the clip-in ring comprising the male component are in contact.
According to a first method of construction, these locking devices are in the form of locking tongues cut in the wall of the said clip-in ring in order that they constitute stops which, when the connector is assembled, co-operate with the shoulder provided for that purpose in the body of the female part.
In accordance with a second method of construction, this clip-in ring is in the form of several tongues arranged co-axially to the pipe to be connected and, at their upper or lower end, are rendered integral by means of an annular part. Also, on their external face, these tongues include a stop which may be introduced into the slot provided for that purpose in the body housing constituting the female part so that it opposes any retraction of the pipe being connected from this latter component.
In any case, it is advantageous to consider that the connector described in this prior document is only applicable to low pressure hydraulic circuits, on the one hand, because of the relative strength and resistance of the locking devices comprising the male component and, on the other hand, the lack of suitable retaining devices.
The locking tongues forming part of the clip-in ring constituting the male component of this rapid type connecter are capable of flexing under the effects of pressure and this may result in the destruction of the connection provided by this type of connector.
Also, as this known rapid type connector is not provided with any means of locking which not only may prevent any accidental release of the male part from the female part but also may be used to ensure correct assembly of these latter components, this known rapid action connector cannot be adapted for any automatic method for its assembly and connection.